The present invention relates to agricultural seeding machines, and, more particularly, to seed placement systems used to place seeds along a desired path and at a desired spacing within a seed trench.
An agricultural seeding machine such as a row crop planter or grain drill places seeds at a desired depth within a plurality of parallel seed trenches formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, ,chains and the like. Each row crop unit has a frame which is moveably coupled with a tool bar. The frame may carry a main seed hopper, herbicide hopper and insecticide hopper. If a granular herbicide and insecticide are used, the metering mechanisms associated with dispensing the granular product into the seed trench are relatively simple. On the other hand, the mechanisms necessary to properly meter the seeds, dispense the seeds at a predetermined rate and place the seeds at predetermined relative locations within the seed trench are relatively complicated.
The mechanisms associated with metering and placing the seeds generally can be divided into a seed metering system and a seed placement system which are in communication with each other. The seed metering system receives the seeds in a bulk manner from the seed hopper carried by the frame. Different types of seed metering systems may be used such as seed plates, finger plates, and seed discs. In the case of a seed disc metering system, a seed disc is formed with a plurality of seed cells spaced about the periphery thereof Seeds are moved into the seed cells, with one or more seeds in each seed cell depending upon the size and configuration of the seed cell. A vacuum or positive pressure air may be used in conjunction with the seed disc to assist in movement of the seeds into the seed cells. The seeds are singulated and discharged at a predetermined rate to the seed placement system.
With a seed metering system including a seed disc as described above, the seed disc typically includes a concentric drive shaft having a sprocket on the outboard end which is driven via a ground drive or the like. The concentrically positioned driven shaft and sprockets may limit the compactness (i.e., reduction in overall size) of the seed metering system.
The seed placement system may be categorized as a gravity drop system or a power drop system. In the case of a gravity drop system, a seed tube has an inlet end which is positioned below the seed metering system. The singulated seeds from the seed metering system merely drop into the seed tube and fall via gravitational force from a discharge end thereof into the seed trench. The seed tube may be curved in a rearward manner to assist in directing seed into the seed trench. The rearward curvature also assists in reducing bouncing of the seeds back and forth within the tube as it falls therethrough into the seed trench. Further, the rearward curvature reduces bouncing of the seed as it strikes the bottom of the seed trench.
A seed placement system of the power drop variety generally can be classified as a seed conveyor belt drop, rotary valve drop, chain drop or air drop. These types of seed placement systems provide more consistent placement of the seeds along a predetermined path at a desired spacing. For more details of these types of seed placement systems, as well as agricultural planting in general, reference is hereby made to the technical document entitled xe2x80x9cPLANTING FUNDAMENTALS OF MACHINE OPERATIONxe2x80x9d; Breece, Edward H., PhD, et al.; Deere and Co.; 1981, which is incorporated herein by reference.
What is needed in the art is an agricultural seeding machine providing an accurate, efficient and compact seed metering system and seed placement system.
The present invention provides a wheel in a seed placement system which defines a seed meter and accelerator. The wheel has three radial zones, including a structural hub, a resilient middle layer surrounding the structural hub, and a gripping outside layer surrounding the resilient middle layer. The gripping outside layer has a relatively high coefficient of friction to engage and carry without damaging the seeds.
The invention comprises, in one form thereof, a seeding machine including at least one seed metering system and at least one seed placement system which is in communication with a corresponding seed metering system. Each seed placement system includes a seed slide and a wheel. The wheel includes a structural hub, a resilient middle layer positioned radially around the hub, and a gripping outside layer positioned radially around the middle layer. The gripping outside layer has a circumferential periphery which is positioned adjacent to at least part of the seed slide. The circumferential periphery has a plurality of contiguous disjoint surfaces.
The invention comprises, in another form thereof, a method of placing seeds with a seeding machine in a trench formed in soil. Seeds are received at a predetermined rate at a seed placement system. The seed placement system includes a seed slide and a wheel. The wheel has a structural hub, a resilient middle layer positioned radially around the hub, and a gripping outside layer positioned radially around the middle layer. The gripping outside layer has a circumferential periphery which is positioned closely adjacent to at least part of the seed slide. The circumferential periphery has a plurality of contiguous disjoint surfaces. The seeds are engaged at the predetermined rate against the wheel periphery. The seeds are carried past at least part of the seed slide with the wheel periphery while maintaining the seeds in contact with the seed slide. Orientation and size variations of the seeds are accommodated by locally deflecting the resilient middle layer during the carrying step. The seeds are released from the wheel periphery to be placed within the trench.
An advantage of the present invention is that the wheel regulates the seeds in a positive manner.
Another advantage is that the bristles at the circumferential periphery of the wheel positively engage the seeds and carry the seeds past the seed slide, regardless of the size and orientation of the seeds.
Yet another advantage is that the gripping outside layer at the circumferential periphery of the wheel may take the form of several different materials having a high coefficient of friction, such as bristles, a foam pad, an expanded foam pad, a mesh pad, a fiber pad and a grit layer.